This document discusses various causes and radiological findings of large bowel obstruction. The most common causes are cancer (60%), diverticulitis (20%), and volvulus (5%). Radiological findings of large bowel obstruction include a peripherally located distended bowel with haustral markings and no air distal to the site of obstruction. Barium enema can demonstrate the level and degree of obstruction, and may show findings like an "inverted U-shaped" sigmoid loop or "bird's beak" sign in sigmoid volvulus. CT scan with oral and IV contrast is also useful to evaluate bowel obstruction and its underlying cause.
6. 1. Carcinoma:
The commonest cause that present with
obstruction.
2. Benign stricture:
Due to Diverticular disease, Ischemia,
Inflammatory bowel disease.
3. Volvulus:
Results from long redundant, faecaly loaded
colon with a narrow pedicle.
4. Hernia.
7. According to Leplac’s law: maximum pressure
is at the it’s maximum diameter, Cecum is at
the greatest risk of perforation .
9. Proximal obstruction: early bilious vomiting.
Distal obstruction:
constipation, distension, vomiting feculent
material (bacterial overgrowth of contents).
Distal obstruction: Less acute onset. Less
prominent .
10. Past Medical Hx: remember to ask about
cardiac history (think about intestinal
ischemia), IBD, gallstones, cancer
Meds: narcotics,antipsychotics
(ileus), diuretics (hypoK / ileus)
recent weight loss (CA).
11. Normal Scout :
Always request:
Supine, Erect and CXR
Gas pattern:
Gastric,Colonic and 1-2
small bowel
Fluid Levels:
Free gas under diaphragm
Look for calcification
Look for soft tissue
masses.
12. look for free air under diaphragm, dilated
bowel loops, air-fluid levels.
Note: if cecal diameter >12cm, there is a risk
of perforation.
Barium enema
Bowel follow-through
CT scan- with PO/IV contrast
13. Large bowel
Peripheral
Max.diameter 8 cm .
Presence of
haustration
Colon is filled with
feces which has
bubbly appearance
Air fluid levels are
few and large.
Small Bowel
Central
Max. diameter 5 cm.
Vulvulae coniventae
Air fluid levels are
many and small .
14.
15.
16. What are the radiological findings of large
bowel obstruction?
Obstructed colon usually appears as a
peripherally located distended bowel with
haustral markings.
No air distal to site of obstruction.
Sometimes the mass may be seen.
17. How is bowel obstruction different from
paralytic ileus?
There will be paucity of gas in bowel beyond
the site of obstruction, unlike in paralytic
ileus where gas can be seen in the rectum.
20. contrast (trip
Used with iv , oral and rectal contrast (triple contrast).
◦ The level and degree of obstruction .
◦ The cause: volvulus, hernia, luminal and mural causes
◦ The degree of ischaemia
◦ Free fluid and gas
◦ Able to demonstrate abnormality in the bowel wall, mesentery,
mesenteric vessels and peritoneum.
Ensure: patient vitally stable with no renal failure and no previous
allergy to iodine iodine
21. Diagnostic points :
◦ Abdominal plain films
Inverted U-shaped appearance of distended sigmoid loop
Loss of haustra
Coffee-bean sign à midline crease corresponding to
mesenteric root in a greatly distended sigmoid
Sigmoid volvulus – bowel loop points to RUQ
Cecal volvulus – bowel loop points to LUQ
Bird’s-beak or bird-of-prey sign à seen on barium enema in
sigmoid volvulus as it encounters the volvulated loop
Apple core appearance : ca colon.
22.
23.
24.
25. Ba contrast enema.contrast-
filled rectum illustrates the
"bird's beak" sign (white
arrow), corresponding to the
luminal narrowing at the site
of sigmoid obstruction. This
is the characteristic
presentation of a sigmoid
volvulus
26. 20 year old woman presented to the ED with
12 hours of abdominal pain, nausea. and
vomiting low grade fever.
No past surgical history
PMH: Polycystic ovarian disease
40. Barium radiograph demonstrates a
typical "apple-core" lesion (arrows)
caused by adenocarcinoma of the
small bowel, producing a partial
obstruction with dilated proximal
bowel.
